The 11-member RCM data represents output from eleven variants of the HadRM3 regional climate model. They were required as part of the UKCP09 methodology, and are available to users as a by-product of UKCP09.
HadRM3 has been used in UKCP09 to produce 11 runs of regional climate projections with the medium emission scenario (A1B), with data saved on a daily time scale. These 11 runs were used to downscale the larger ensemble of GCM runs.
It was decided that the 11-member RCM output should be made available alongside UKCP09, as it provides useful additional data - including transient, daily climate projections for a larger range of climate variables - that could not be delivered as probabilistic projections.
However, it should be remembered that since the 11-member RCM data has various limitations, such as that it does not explore modelling uncertainty as thoroughly as the standard UKCP09 outputs and only describes changes for one emissions scenario. It is also not as readily accessible as the UKCP09 information and does not have a similar level of user support accompanying it.
- The 11-member RCM data is described here on the UKCP09 website and in Chapter 5 of the UKCP09 Climate change projections report.
- Some worked examples were developed prior to the launch of UKCP09 that used dummy outputs to examine how the 11-member RCM output might be used. The worked examples should not be interpreted as a best practice method for using UKCP09, but as one way of using the outputs.
- More details about the climate models used in UKCP09 are given in Box 2.1 in the UKCP09 Climate change projections report. A commentary about the strengths and weaknesses of climate models is given in Annex 3.
Find out more
- The 11-member RCM dataset is available on the LINK website